The gap ends are proven primes with 18662 digits.
n# (called n primorial) is the product of all primes ≤ n. The form increased
the chance of a large gap compared to random numbers.
Primality proofs were made with Primo.
The gap has merit 25.90 and is the first known "megagap" (above 1 million)
satisfying the requirement at Top-20 gaps with merit above 20.
It is also the first megagap with proven end points.

The merit of a prime gap is defined as (gap size)/log(gap start). By the prime
number theorem, this gap is around 25.9 times larger than the average gap for primes of that
size.
Sieving was done with APTreeSieve, a C program using the GMP library.
PrimeForm/GW made 3-prp tests of the unfactored numbers.

The prime factors up to 43103 are easy to reproduce. The factors from 43117 to
10^11 are in gap1113106factors.zip.
They have been verified by an independent program. PrimeForm/GW has made
multiple Fermat 3-prp tests on each number with no factor below 10^11.
The 64-bit residues are in gap1113106residues.zip.
All residues matched in pfgw32 and pfgw64 runs on 3 different computers varying
between no -a parameter and -a1, -a2, -a3. Different -a parameters choose a
different sized FFT and therefore make different computations of the same
residue. Dana Jacobsen has also made an independent verification of the
composites with a C program using the GMP library to make BPSW primality tests.

The gap was originally announced 8 March 2013 with prp's as gap ends. The Primo
certifications took 94 days and 86 days on an Intel i7-3960X on an ASUS Sabertooth X79
motherboard boosted at 4.50 GHz. The certificates are linked at the Primo
Top-20 where they are the 2nd and 3rd largest as of October 2013, only 4
digits below the largest.